Ignition distributor having current-conductive segments in two groups of opposite polarity



Sept. 19, 1967 W. a. SMITH ETAL 3,342,955

IGNITION DISTRIBUTOR HAVING CURRENT-CONDUCTIVE SEGMENTS IN TWO GROUPS OF OPPOSITE POLARITY Filed Oct. 24, 1965 Ava/Mike United States Patent 3,342,955 IGNITION DISTRIBUTOR HAVING CURRENT- CONDUCTIVE SEGMENTS IN TWO GROUPS OF OPPOSITE POLARITY William C. Smith, 221 W. Morgan Ave., Chesterton, Ind. 46304, and Reinhardt W. Carlson, 7545 Forest Ave., Munster, Ind. 46321 Filed Oct. 24, 1965, Set. No. 504,390 6 Claims. (Cl. ZOO-19) ABSTRACT OF THE DISCLOSURE An ignition distributor for a primary circuit in which a grounded housing includes a plurality of groups of arcuate current conducting segments alternately arranged and circumferentially spaced about the inner surface of a circular wall, one of the groups being grounded to the housing and the other group being connected to a primary coil in a series circuit with a grounded source of current, and in which an insulated rotor includes on a radial arm a contact which sweeps the two groups of arcuate segments for alternately discharging the coil and in which the contact is normally spring urged toward the segments and centrifugally urged there toward as the rotor rotates.

Our invention relates to ignition distributors for motor car engines, and more particularly to the mechanism therein which generates the fuel-igniting spark. The conventional instrumentality for this purpose is a cam on the distributor shaft which induces the periodical separation of a pair of breaker points in the secondary ignition circuit. While these points are made of carbon alloy, they require accurate adjustment and become corroded from burning, so that their efiiciency is impaired. Also, in conventional distributors the grounding is through the ground contact of the contact point set, which is fastened to the mounting plate inside the distributor.

In view of the above condition, it is one object of the present invention to provide a distributor in which the contact break is accomplished by a rotor in positive contact with a series of current-conductive segments, with contact intensified as the speed of the rotor is increased.

A further object is to provide a series of current-conductive segments in two groups of opposite polarity, the segments in one group alternating with those in the other, and a grounded metallic housing to which one series of segments is directly attached for grounding the same efficiently.

A still further object is to provide a spark-generating mechanism which is simple, sturdy and adaptable without material change to suit either a six-cylinder or an eightcylinder engine.

A better understanding of the invention may be gained by reference to the accompanying drawing, in which FIG. 1 is a vertical section of the improved distributor;

FIG. 2 is a section on the line 2-2 of FIG. 1; and

FIG. 3 is a horizontal section of the distributor housing, showing an electrical circuit for the segments mentioned above, suitable for a six-cylinder engine.

Referring specifically to the drawing, denotes the metallic housing of the distributor, which is grounded by direct attachment to the motor car engine. The drive shaft 11 and the parts in the upper portion of the distributor are of conventional design, the present invention being located between the cam 11a of the drive shaft and the wall of the housing 10.

FIG. 1 shows that the wall of the housing 10 has an internal shoulder 10a which seats a horizontal ring 13 of insulating material. Since the ring 13 must maintain a stationary position, it is driven down with a tight fit; and a vertical key may be included in the fit of the ring to insure it against turning or creeping relative to the housing.

The ring 13 has cemented or otherwise attached to its inner surface a circular series of segments 15 and 16, these being separated endwise by narrow spaces 15a. When the distributor serves a six-cylinder engine, the number of segments is six, and when the engine has eight cylinders the number of segments is eight. The segments are thin and preferably strips of copper to serve efliciently as conductors of electricity while resisting surface wear.

The shaft cam 11a receives a tightly-fitted rotor 17 of insulation material, the same tapering sidewise with an arm 17a. The latter is opposite the circular series of segments 15 and 16, and carries a brush of band form 18 designed to make wiping contact with the segments when the rotor is in operation. The arm 17a is recessed at 17b to seat the shank of the brush; and such shank is perforated for the application of a screw 21 to secure the brush to the rotor. The brush has return end loops 18a disposing a pair of blades 18b and 180 in surface contact with the segments; and the brush is completed by a concave section 18d between the blades 18b and 180.

The segments 15 and 16 are in an electrical circuit illustrated in FIG. 3. Thus, the segments 15 shown are in a group of three and alternate with those in a group of the segments 16. Also, the segments in the group 15 are interconnected by a conductor 15b, while those in the group 16 are interconnected by a conductor 16b. The conductor 15b has a lead to the wall of the housing 10; and the grounding of the latter is illustrated by a lead 15a to a ground 15 The conductor 16b is lead to the negative terminal of an ignition coil 20. A conductor 22 extends from the positive terminal of the coil by way of the motor car ignition switch 23 to a battery 25. For purposes of compactness, FIG. 2 shows that the ring 13 is grooved peripherally, as seen at 13a, to accommodate the conductors 15b and 1611.

When the distributor shaft is in rotation, the brush 18 travels in wiping contact with the series of segments. The group of segments 15 is on the positive side of the circuit, and the group 16 on the negative side thereof. FIG. 2 shows that the brush 18 has its blade 18b on a positive segment 15 and its blade on a negative segment 16. This indicates that there is a flow of current through the brush, and that the ignition coil is saturated. When the rotor turns in clockwise directionas seen in FIG. 2- the blade 18c leaves the negative segment 16, and both blades engage the next positive segment 15. Now there is no current flow, and a spark will occur in a correspond ing engine cylinder. As the rotor continues to turn, the blade 18b will assume contact with the next negative segment 16, while the blade 180 is still in contact with the positive segment 15. Now the flow of current in the brush is reversed, and the operation of the distributor will continue to generate the spark for the next engine cylinder to be fired, and so on, to keep the six cylinders firing in the proper order.

The shank 18 and loops 18a are preferably made of spring steel in order to exert pressure at all times against the segment series for good electrical contact. However, the blades 18b and 18c and their connecting section 18d are made of copper-either fully or as a shoe for the brush-for good electrical conductivity. The length of the blades 18b and 18c may be varied to obtain a desired dwell, although this factor will not affect the operation of the distributor in the manner that conventional breaker points-set too close or too far apartdo. It is known that breaker points set too close will arc across when opened, and if set too wide will not close long enough for the proper saturation of the coil. Also, the sweep of the rotor is in a smaller circle than the series of segments 15-16, forming a positive connection between the coil wires 16b and 150. This means that there will always be a clean break of the current, a condition not always true where breaker points are used.

An important advantage in the application of the brush 17 to segments supported in an outer circle is that the brush, by its flexibility will expand from centrifugal force as the speed of the engine increases to insure an even more positive engagement with the segments. A further advantage of the present construction lies in the changes of polarity in the segments as the brush travels, which prevents burning of the brushes. Further, as mentioned before, the negative segments are grounded directly to the fixed and properly grounded distributor housing instead of the center shaft which grounds through a lubricated bearing. This factor also relieves the brush of tendencies to burn and corrode as it crosses the gaps between the segments. Finally, it is apparent that the novel brush and segments are an installation which is simple and easily accessible for attention or replacement.

We claim:

1. An ignition distributor for a primary circuit comprising in combination:

a primary circuit including in series a coil and a grounded source of current;

a casing grounded in said circuit and having a circular wall;

an insulated rotor journaled for 360 of rotation within said wall and having an arm extending radially toward the inner surface of said wall for sweeping thereby during rotation of said rotor;

an insulation ring in said housing in spaced, opposed relation from the terminal end of said arm;

two groups of circumferentially spaced, arcuate, current-conducting segments on said insulation ring, segments of one group being interposed between segments on the other group so that the segments are alternately disposed on said wall,

one group of segments being electrically connected to said housing and grounded therethrough, the other group of segments being connected in seties to said coil; and

contact means secured to the terminal end of said arm,

said contact means having a circumferential span less than the arc of one of said segments whereby polarity of the segments of the groups are alternately reversed as the coil is alternately charged and discharged.

2. The structure as claimed in claim 1 in which said contact means comprises an endless band disposed transversely of one end of said arm and secured at one side thereto, said band being resiliently compressed between the terminal end of: said arm and said segments for minimizing arcing and being centrifugally urged into contact with said segments as the arm rotates.

3. The structure as claimed in claim 2 in which said arm included a terminal, transverse groove, said endless band being seated in and fixedly secured in said transverse groove.

4. The structureas claimed in claim 3 in which said endless band includes a free, intermediately indented portion defining outer blades for minimizing arcing during simultaneous engagement with adjacent segments.

5. The structure as claimed in claim 2 in which said band comprises spring steel, and that portion engaging said1 segments includes a copper surface on said spring stee 6. The structure as claimed in claim 1 in which said insulating ring includes a circumferential groove about the outer periphery thereof and opening toward the inner surface of said circular wall, a pair of current conductors disposed in said groove and mutually insulated from each other, one of said current conductors being electrically connected between said one group of segments and said housing and ground the same to said housing, said other conductor being electrically connected between said other group of segments and said coil.

References Cited UNITED STATES PATENTS 1,577,572 3/1926 Forder 20026 1,625,001 4/1927 Volkmar 20026 1,628,902 5/1927 Nickell et al. 20026 2,498,805 2/ 1950 Gurevsky 2008 FOREIGN PATENTS 18,949 8/ 1907 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

H. BROOME, Assistant Examiner. 

1. AN IGNITION DISTRIBUTOR FOR A PRIMARY CIRCUIT COMPRISING IN COMBINATION: A PRIMARY CIRCUIT INCLUDING IN SERIES A COIL AND A GROUNDED SOURCE OF CURRENT; A CASING GROUNDED IN SAID CIRCUIT AND HAVING A CIRCULAR WALL; AN INSULATED ROTOR JOURNALED FOR 360* OF ROTATION WITHIN SAID WALL AND HAVING AN ARM EXTENDING RADIALLY TOWARD THE INNER SURFACE OF SAID WALL FOR SWEEPING THEREBY DURING ROTATION OF SAID ROTOR; AN INSULATION RING IN SAID HOUSING IN SPACED, OPPOSED RELATION FROM THE TERMINAL END OF SAID ARM; TWO GROUPS OF CIRCUMFERENTIALLY SPACED, ARCUATE, CURRENT CONDUCTING SEGMENTS ON SAID INSULATION RING, SEGMENTS OF ONE GROUP BEING INTERPOSED BETWEEN SEGMENTS ON THE OTHER GROUP SO THAT THE SEGMENTS ARE ALTERNATELY DISPOSED ON SAID WALL, ONE GROUP OF SEGMENTS BEING ELECTRICALLY CONNECTED TO SAID HOUSING AND GROUNDED THERETHROUGH, THE OTHER GROUP OF SEGMENTS BEING CONNECTED IN SERIES TO SAID COIL; AND CONTACT MEANS SECURED TO THE TERMINAL END OF SAID ARM, SAID CONTACT MEANS HAVING A CIRCUMFERENTIAL SPAN LESS THEN THE ARC OF ONE OF SAID SEGMENTS WHEREBY POLARITY OF THE SEGMENTS OF THE GROUPS ARE ALTERNATELY REVERSED AS THE COIL IS ALTERNATELY CHARGED AND DISCHARGED. 